I got the latest version, and I'm definitely not changing the cursor multiple times per frame. I made the cursor change extra slow for this gif so you can see the impact more clearly:
If I change the cursor in the step event instead of a draw event, the same thing happens but with the red bar.
Here's another gif from a much more hectic room with lots of stuff going on.
If you decide to take a look at it and there's anything I can do to help, please let me know!
Really sorry to hear about the 64-bit runtime breaking all your DLL's. Hopefully you can figure out some quick fixes along the way to save yourself time.